Gas powered water heaters are used to heat and store a quantity of water in a storage tank for subsequent on-demand delivery to plumbing fixtures such as sinks, bathtubs, showers, and appliances in residential and commercial buildings. Gas water heaters typically utilize a combustible gas source coupled to an air source for providing oxygen necessary for combustion. The gas and air are typically combusted in a combustion chamber at a burner beneath a water storage tank.
When a combustion area proximate the burner rises to a sufficient temperature, nitrogen present in the combustion area becomes reactive with uncombusted oxygen in the combustion chamber, thereby producing nitrogen oxides (NO and NO2, or collectively, NOx), the emission levels of which can be subject to environmental controls.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention.